Food Safety
Ata Kaboudari
Abstract
The aim of this study was to investigate the changes in antibiotic susceptibility /resistance of bacteria isolated from biofilms in the presence of freezing stress in different meat juices (beef, mutton and goat). Gram-positive and Gram-negative bacteria of food origin (Listeria monocytogenes and Salmonella ...
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The aim of this study was to investigate the changes in antibiotic susceptibility /resistance of bacteria isolated from biofilms in the presence of freezing stress in different meat juices (beef, mutton and goat). Gram-positive and Gram-negative bacteria of food origin (Listeria monocytogenes and Salmonella enterica ser. Typhimurium) were selected. Meat juice model was selected as a nutritious and complex environment containing a wide range of different compounds. Biofilms were studied in 96-well microplates and disk diffusion method was used to measure the antibiotic susceptibility. The results showed that the bacteria isolated from biofilms in meat juice models and freezing conditions exhibited significant changes in their antibiotic susceptibility. Long-term freezing (3 weeks and 1 month) significantly increased the antibiotic resistance. Both bacteria became resistant to chloramphenicol. The results indicated that foods should not be subjected to long-term freezing conditions so that existing pathogens do not acquire the ability to resist antibiotics.
Food Safety
Ata Kaboudari; Tooraj Mehdizadeh
Abstract
Salmonella is responsible for causing significant morbidity and mortality in both humans and livestock annually. The development of antibiotic resistance in these bacteria is attributed to their exposure to various environmental stresses. Given the increase in antibiotic resistance in Salmonella, this ...
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Salmonella is responsible for causing significant morbidity and mortality in both humans and livestock annually. The development of antibiotic resistance in these bacteria is attributed to their exposure to various environmental stresses. Given the increase in antibiotic resistance in Salmonella, this study aimed to investigate the simultaneous effects of food-related stresses on the antibiotic susceptibility pattern of Salmonella Typhi. The stresses included osmotic pressure (1 and 4%), pH (7.3 and 5), heat (45 and 55 °C), cold (4 and 8 °C), and freezing (24 and 96 h). Changes in the antibiotic susceptibility patterns of S. Typhi were investigated using the disk diffusion method. The results showed that osmotic pressure and freezing time had the greatest effects on antibiotic susceptibility. Different stresses have different effects on the antibiotic susceptibility patterns of S. Typhi. The results of this study can be used as a basis for further research in this area.
